DESIGN STANDARDS AND METHODS FOR OPEN RECTANGULAR STORAGE TANKS 2

[jamesh8448]

I have been trying to find recognized standards regarding design of large open rectangular storage tanks. My company has acquired this product line recently with no backup calculations. There are many sizes. I would like to check the designs, and also determine what modifications are necessary to handle seismic loading.

 

[arto]

Look in O.W.Blodgett's "Design of Weldments" ch.4.3 & 4.6 or "Design of Welded Structures," ch 6.4 & 6.5

Available from

https://ssl.lincolnelectric.com/foundation/

for $10 or $15 - such a deal!!

 

[LSThill]

Hi jamesh8448 (Mechanical)

RE: Pressure Vessel Handbook by Eugene F. Megyesy, Pressure Vessel Publishing O. O. Box 35365, Tulsa OK 74154, isbn 0-914458-19-1

RECTANGULAR TANKS PAGE 213, 214 , 215, 216, 217, 218, 219, 220.

Price is about $110.00USD

Leonard@thill.biz

http://www.thill.biz

 

[MJCronin]

james,

There are no "recognized design standards" for rectangular tanks like there are for vertical, flat-bottomed atmospheric tanks ( API-650 for example )

The above two posts cite books with methodologies for performance of design calculations...... but there are no standards. Rectangular tanks, as you probably know, are structurally inefficient as compared with cylindrical tanks. They are an expensive way to store liquids.

A couple of years back, my company did a study of a new resin storage facility for a local paint company. The new building was to have a special ventilation systems and twelve rectangular stainless steel tanks, each 12,00 to 14,000 gallons. The cost of storage was over three times that of the traditional "tank farm" with cylindrical API-650 designs.

Good luck.......

Let us know how you make out with your search...


MJC

 

[Feitor]

The calculation presented in Megyesy's book has some inconsistensis. I would rather to use the stress calculation considering the Roarks' book formula.

 

[jamesh8448]

Feitor, I have Megyesy's book. I have noticed some errors and omissions as well in this section, but not in the formulas. Are there errors in his formulas I should be aware of?

 

[LSThill]

jamesh8448 (Mechanical)

STADD PRO Structural Analysis and Design by Research Engineers International: RECTANGULAR STORAGE TANKS.

Also, AWS D1.1 (AMERICAN WELDING SOCIETY.

Leonard@thill.biz

http://www.thill.biz

 

[JOHNPIA2]

I concur that Megyasy's method is not safe, from personal experience!

 

[kenvlach]

Open top, rectangular tanks are used for processing in the metal finishing industry. MJCronin is right re cylindrical being cheaper for storage, but sometimes limited floor space matters.

I don’t see the need for expensive references. I have used Design of Welded Structures, section 6.5 (cited by arto) for tanks up to 6.5 ft deep containing hot electropolishing acidic solution of SG 1.68. Made a tank like Figure 4, p. 6.5-5, except used a 2nd horizontal stiffener and threw in some verticals to handle about 2600 pounds of workload on the top flange.
To reinforce an old anodizing tank with a corroded steel frame inside fiberglass, I fabbed a girth rib of steel angle, bolted at the corners, with flats against the outer fiberglass wall, calculated similar to Figure 4.

For seismic considerations, just factor the maximum lateral acceleration into the SG of the liquid, e.g., if 0.2 G, multiply the liquid’s SG by 1.20 in your design.
[Note: presuming flat bottomed tanks, not up on legs]

Of course, all inside welds must be continuous, there are proper designs for inlets & outlets, etc. I suggest you read Electroplating Engineering Handbook, 4th Edn., or the article “Chemical-Resistant Tanks and Linings” at

http://www.metalfinishing.com/WZ/Me...etalGB_FinishingPlantEngineering/000013/show/

for more design considerations.

One additional comment: If working with stainless steel, it is usually cheaper to bend shapes from sheet rather than buying angle or channel. You can also buy oversized sheet and do some bending to minimize welding. On the 6.5 ft deep tank mentioned above, the top flange and lip were were from same sheet as the wall and a portion of the floor.

 

[Raydel]

The flat panels of a rectangular storage tank can be designe with regard to thickness, but the real problem is to determine the steel structure that stiffens the sides of the tank. The whole design can be accomplished using standard structural methods, but two things must be born in mind: (1) be careful of the deflection, and (2) make the unbroken stiffener lie along the short side of the tank (usually the vertical height of a long tank), and the broken stiffeners along the long side (usually the length of the tank). Using simple methods it is not difficult to do the job, but a trial and error approach is often necessary.